Add loop printing to block comments.

runtime/vm/flow_graph.h

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_FLOW_GRAPH_H_
 #define VM_FLOW_GRAPH_H_
 
 #include "vm/growable_array.h"
 #include "vm/hash_map.h"
 #include "vm/intermediate_language.h"
@@ skipping 204 matching lines @@
 
   // Returns true if every Goto in the graph is expected to have a
   // deoptimization environment and can be used as deoptimization target
   // for hoisted instructions.
   bool is_licm_allowed() const { return licm_allowed_; }
 
   // Stop preserving environments on Goto instructions. LICM is not allowed
   // after this point.
   void disallow_licm() { licm_allowed_ = false; }
 
-  const ZoneGrowableArray<BlockEntryInstr*>& loop_headers() {
+  const ZoneGrowableArray<BlockEntryInstr*>& LoopHeaders() {
     if (loop_headers_ == NULL) {
       loop_headers_ = ComputeLoops();
     }
     return *loop_headers_;
   }
 
+  const ZoneGrowableArray<BlockEntryInstr*>* loop_headers() const {
+    return loop_headers_;
+  }
+
+  // Finds natural loops in the flow graph and attaches a list of loop
+  // body blocks for each loop header.
+  ZoneGrowableArray<BlockEntryInstr*>* ComputeLoops() const;
+
   // Per loop header invariant loads sets. Each set contains load id for
   // those loads that are not affected by anything in the loop and can be
   // hoisted out. Sets are computed by LoadOptimizer.
   ZoneGrowableArray<BitVector*>* loop_invariant_loads() const {
     return loop_invariant_loads_;
   }
   void set_loop_invariant_loads(
       ZoneGrowableArray<BitVector*>* loop_invariant_loads) {
     loop_invariant_loads_ = loop_invariant_loads;
   }
@@ skipping 46 matching lines @@
   void RemoveDeadPhis(GrowableArray<PhiInstr*>* live_phis);
 
   void ReplacePredecessor(BlockEntryInstr* old_block,
                           BlockEntryInstr* new_block);
 
   // Find the natural loop for the back edge m->n and attach loop
   // information to block n (loop header). The algorithm is described in
   // "Advanced Compiler Design & Implementation" (Muchnick) p192.
   // Returns a BitVector indexed by block pre-order number where each bit
   // indicates membership in the loop.
-  BitVector* FindLoop(BlockEntryInstr* m, BlockEntryInstr* n);
-
-  // Finds natural loops in the flow graph and attaches a list of loop
-  // body blocks for each loop header.
-  ZoneGrowableArray<BlockEntryInstr*>* ComputeLoops();
+  BitVector* FindLoop(BlockEntryInstr* m, BlockEntryInstr* n) const;
 
   Isolate* isolate_;
 
   // DiscoverBlocks computes parent_ and assigned_vars_ which are then used
   // if/when computing SSA.
   GrowableArray<intptr_t> parent_;
   GrowableArray<BitVector*> assigned_vars_;
 
   intptr_t current_ssa_temp_index_;
   intptr_t max_block_id_;
@@ skipping 122 matching lines @@
   // Per block sets of available blocks. Block A is available at the block B if
   // and only if A dominates B and all paths from A to B are free of side
   // effects.
   GrowableArray<BitVector*> available_at_;
 };
 
 
 }  // namespace dart
 
 #endif  // VM_FLOW_GRAPH_H_